Bio-enzyme mediated conditioning strategies for enhanced dewaterability of construction-related dredged sludge

Performance and mechanisms of dredged sludge dewaterability enhancement with slag-based polymeric titanium aluminum coagulant

With the increasing wastewater generation from domestic and industrial activities due to the rapid economic development, the generation of sludge, in particular dredged sludge from municipal sewer system, has been an issue in developing countries. This study evaluated the enhancement of sewer’s sludge dewatering via mixingthe sludgewith different agro-wastes, including corn core powder, rice husk powder, bagasse powder and peanut shell powder. The addition of these agro-waste powders helped decrease the sludge’s moisture contents up to 17% while increase the organic matters nearly to 40% after mixing with the ratio of agro-wastes and sludge of 1:3. Statistical analysis revealed the impacts of both additive types and mixing ratio on moisture content reduction. Among the four types of agro-waste, rice husk was shown to be the best additive to dredged sludges with highest reduction of heavy metal concentration and moisture content. The addition of agro-waste powders to enhance the dewatering of sludges is promising in the context of promoting waste reuse and energy saving.